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Comment by tazjin | Hacker News Reader

A good chance to learn why people who write reliable software almost universally like static type systems.

This code would pass static type validation, there's nothing wrong with it at that level. It gets a default value to use and does exactly that.

Sure, you can follow along the old meme: https://twitter.com/vbhvsgr/status/1419369352164372482

Though in practice in decent languages it's much less likely you'd write your own `any -> any, any`-typed library for whatever (in this case DB interactions), and use a strongly typed one in which this would at least have been a much more explicit mistake to make.

But this isn't an `any -> any` case. They passed in a default value, as a string, which is the correct type for a default value for this column. Even with very strong typing they wouldn't have got a type error here right?

You can forbid static values and require it to be a function.

Generally, static languages will just culturally be less likely to have this kind of invisible "T | (() -> T)" overload.

You could make a special primary key column creation function that rejects static values.

You don't even have to reject/forbid them, just make their use explicit.

I thought this was going to be the xkcd ‘int rand() {return 6; //chosen by fair dice roll}’, which is more or less what they did lol.

If the language in question disallows function overloading, this distinction becomes very clear. For an example, see Rust option's unwrap_or[1] vs unwrap_or_else.

[1] https://doc.rust-lang.org/std/option/enum.Option.html#method...)

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